1. Field of the Invention
This invention relates to ultrafine particles of amorphous metal and a method for the production thereof.
2. Description of the Prior Art
Heretofore, various methods have been introduced for the production of ultrafine particles of metals. For example, Japanese Patent Application, KOKAI (Early Publication) No. 2-294,417 discloses a method for producing an ultrafine copper powder by decomposing copper hydride and Japanese Patent Application, KOKAI No. 2-38,505 discloses a method for producing an ultrafine metal powder by subjecting a metal powder to repeated oxidation and pulverization thereby forming ultrafine metal oxide particles and reducing the particles in an atmosphere of high-temperature plasma containing a reducing gas and, at the same time, conferring a spherical shape on the particles. These ultrafine particles of metals have been used as high-quality magnetic materials for magnetic tapes, as sintering additives, and the like, depending on the characteristics inherent in their raw materials. The ultrafine metal particles which are obtained by the methods cited above, however, possess a crystalline structure.
Incidentally, amorphous alloys are inherently suitable as high permeability materials because they have their component atoms substantially randomly adjoin their neighbors and are devoid of magnetic anisotropy due to symmetry. Further, the amorphous materials are at an advantage in exhibiting high mechanical strength, offering high electrical resistance, and manifesting excellent resistance to corrosion in addition to excelling in magnetic characteristics.
Generally such methods as rapid solidification, vacuum deposition, and sputtering are adopted for the production of amorphous materials. These methods, however, are specifically intended for the production of materials which are thin ribbons, wires, and films in shape.